1. It should always be the consistency of pancake batter.
2. You don't have to baby it as much as you think or as often as people/cookbooks tell you. More on this later.
What you should do first is call your local bakery (but not your chain grocery store) and ask if you can buy a cup of their sourdough starter. They may say no, but it's worth a shot. It'll save you some time if you don't have to make your own. You also can buy starter from King Arthur Flour and have it shipped to your house. Theirs is 240 years old. Mine is 13 years old (I got it from a cooking school in Denver when I took a bread class). If you already have a cup of starter, skip down to Building Your Starter.
Here's an easy way to make your own starter.
Print these directions
Making Your Starter
2 cups warm water
1 tablespoon of sugar or honey (optional)
1 tablespoon or packet active dry yeast
2 cups all-purpose flour
Pour the water into a glass bowl, add the sugar/honey and yeast. Stir to dissolve. Add the flour and stir until the flour is fully hydrated. Cover with a dishcloth or towel and set in a warm place (or at room temperature). Let it set for 2-5 days, stirring once or twice a day. It should be bubbling during this time. Once it stops bubbling and smells sour, stir it once more, use it, or cover and refrigerate. I keep my starter in an 8-cup Tupperware container. You can now skip to Using and Maintaining Your Starter.
Building Your Starter
If you bought a starter, measure 1 cup of it into a bowl. You will be doubling the volume every time you feed it so make sure your bowl is big enough. Add in 1/2 cup all-purpose flour and 1/2 cup water. Stir, cover, and let sit at room temperature for one day. After one day, add in 1 1/4 cups flour and 3/4 cup water. Stir, cover, and let sit at room temperature for two days. After two days, add in 2 1/2 cups flour and 1 1/2 cups of water. Stir and let sit at room temperature for 2 days. Now you can use it. This gives you 8 cups of starter. This is the amount of starter I have and use for two people. We always have more than plenty.
Using and Maintaining Your Starter
When you use your starter, you want to replace what you used with flour and water. Now, you can measure out the flour and water (if you used 2 cups, you'll add about 1 1/4 cup flour and 3/4 cup water) or you can dump in some flour and add some water until it's the consistency of pancake batter again. That's what I do. I try not to over think it. It's just starter, and I have more important things to think about. Make sure you always have at least 2 cups of starter.
Unless you are using your starter every few days, store it in the refrigerator because this will keep it from going bad. If you see liquid on top, this means it's hungry and needs to be fed with water and flour. You'll want to pull your starter out of the fridge a few days before you want to use it, dump out a couple cups of it (into the trash/drain or there are some recipes that use an unfed starter), replace what you dumped out with more flour and water, and let it sit and ferment for a couple of days. Then it's ready for you to use.
A lot of people say you need to use your starter every week or two weeks. I usually go at least a month and it's fine. It's very hungry, and there's a thick layer of nasty water on top of it, but that's ok. I dump out some starter, add some flour and water until it's the consistency of pancake batter, let it sit for a couple of days and then use it. After I use it, I add a little more flour and water to replace what I used, stir it up, and put it back in the fridge.
The moral of the starter story is don't over think it. It doesn't have to be precise. And in the world of baking where precision is everything, isn't it nice to have something that you can dump some water and flour into, stir, and let it do the work? Let me know how your starters are coming along or if you have questions. Tomorrow there will be a great sourdough cheddar roll recipe that will knock your socks off!